RSPM level refers to the amount of suspended dust particles that can enter the human respiratory system. It is one of the parameters that determine the extent of Air pollution. Higher the RSPM levels, higher will be the exposure to human health risks associated with the dust inhalation.

The minister said that around 54.4 tons of dust is generated daily and 42% of which comes from vehicular emissions. The dust present on roads, caused due construction activities, industries, generators, and domestic activities contribute around 20%, 14%, 14%, 7% and 3% respectively towards dust generation.

The Whitefield Industrial Zone has the highest level of respirable suspended dust in Bengaluru with RSPM level of 230 milligrams per cubic meters of air as against the national permissible RSPM level of 60 milligrams per cubic meters.

On the other hand, the NO2 and SO2 levels have been found to be within the permissible levels in Bengaluru.

Situation across the nation:

According to a report from Central Pollution Control Board (CPCB), between 2001 and 2007, the RSPM levels for all metros except Chennai have been above permissible limits. The RSPM levels for Delhi has increased from 120 micrograms per cubic meters in 2001 to 160 micrograms per cubic meters in 2007. For the same period, the RSPM levels have increased from 80 to 100 micrograms per cubic meters in Mumbai.

Kolkata recorded RSPM level of 140 micrograms per cubic meters in 2007. Only Chennai recorded 50 micrograms per cubic meters which is below the national permissible limit. The levels of SO2 for these metros between the years 2001-2007 have remained below the permissible limits of 50 per cubic meters.

According to Chandigarh Pollution Control Committee, the RSPM levels for Chandigarh in 2014 was well beyond the national permissible limits. In Industrial area, it was at 114 micrograms per cubic meters, almost twice the permissible limits.

Rising vehicular traffic is one of the major contributors towards increasing RSPM levels. Industrial and Domestic activities are other sources of air pollution.

Effect of RSPM on human health:

Most of the particles inhaled by the body are removed out of the body through nostrils. Smaller ones may pass through the windpipe and get stuck into protective mucus and be removed later on. But the smallest of these particles with their size less than or equal to 10 microns (called as RSPM) gets deposited in the air sacs of lungs.

These deposited tiny particles interfere with respiratory actions like an exchange of carbon dioxide with oxygen. This places extra pressure on the heart and will cause acute shortness of breath.

Hence, RSPM can cause extensive damage to the respiratory system. It will lead to difficulty in breathing, aggravated coughing and decreased functioning levels. It may lead to cardiopulmonary problems, asthma, bronchitis, and in extreme cases, premature deaths.

Steps to reduce air pollution:

To reduce the levels of RSPM in Bengaluru, the Karnataka State Pollution Control Board (KSPCB) had issued a 13-point direction to Transport and other government departments according to the report in The Hindu.

The remedial measures that have been suggested include creating dedicated bus lanes, increasing green covers, banning vehicles having 2 strokes and those which are older than 15 years, restrictions on the movement of heavy vehicles, clearing of encroachment and filling of potholes.

In 2003, the Supreme Court of India directed the respective state governments to prepare action plans to bring down the RSPM levels in Ahmedabad, Kanpur, Sholapur, Lucknow, Bangalore, Chennai, and Hyderabad.

Industrial Pollution: Shifting of Industries from non-conforming zones, switching over to clean technologies, using clean fuels, installation of Pollution control Devices, Development of green belt, etc.

Vehicular Pollution: Implementation of the emission norms as well as fuel quality in accordance with the road map proposed by the Auto Fuel Policy, switching over to clean alternate fuels like CNG, LPG & Bio-fuels, augmentation in Public Transport system, Better traffic management.

Domestic Pollution: Ban on open burning of garbage, biomass, etc. and augmentation on the supply of LPG as cooking fuel etc.

But the measures that have been taken across various cities till date appear to be insufficient to bring the RSPM level below the permissible levels. Instead, the rising vehicular populations and increasing factories and industries are making the situation worse. The city and state administrations must pursue this issue seriously and should try to bring the RSPM below the permissible level as soon as possible.

Packs of flattened polyethylene terephthalate (or PET) bottles are carried into a depot before being pulverized as part of a recycling process at Tokyo PET Bottle Recycle Co. in Tokyo, Aug. 13, 2002. Researchers in Britain and the United States have engineered an enzyme that breaks down such plastics. VOA

Scientists in Britain and the United States say they have engineered a plastic-eating enzyme that could help in the fight against pollution.

The enzyme is able to digest polyethylene terephthalate, or PET — a form of plastic patented in the 1940s and now used in millions of tons of plastic bottles. PET plastics can persist for hundreds of years in the environment and currently pollute large areas of land and sea worldwide.

Researchers from Britain’s University of Portsmouth and the U.S. Department of Energy’s National Renewable Energy Laboratory made the discovery while examining the structure of a natural enzyme thought to have evolved in a waste-recycling center in Japan.

Finding that this enzyme was helping a bacteria to break down, or digest, PET plastic, the researchers decided to “tweak” its structure by adding some amino acids, said John McGeehan, a professor at Portsmouth who co-led the work.

This led to a serendipitous change in the enzyme’s actions — allowing its plastic-eating abilities to work faster.

“We’ve made an improved version of the enzyme better than the natural one already,” McGeehan told Reuters in an interview.

“That’s really exciting because that means that there’s potential to optimize the enzyme even further.”

The team, whose finding was published Monday in the Proceedings of the National Academy of Sciences journal, is now working on improving the enzyme further to see if it could be capable of breaking down PET plastics on an industrial scale.

Plastic pollution, Pixabay

“It’s well within the possibility that in the coming years we will see an industrially viable process to turn PET, and potentially other [plastics], back into their original building blocks so that they can be sustainably recycled,” McGeehan said.

‘Strong potential’

Independent scientists not directly involved with the research said it was exciting, but cautioned that the enzyme’s development as a potential solution for pollution was still at an early stage.

“Enzymes are non-toxic, biodegradable and can be produced in large amounts by microorganisms,” said Oliver Jones, a Melbourne University chemistry expert. “There is strong potential to use enzyme technology to help with society’s growing waste problem by breaking down some of the most commonly used plastics.”

Douglas Kell, a professor of bioanalytical science at Manchester University, said further rounds of work “should be expected to improve the enzyme yet further.”